package com.tdd;

import static org.junit.Assert.assertEquals;

import java.math.BigDecimal;

import org.junit.Before;
import org.junit.Test;

public class RpnCalculatorTest {
	private RpnCalculator rpnCalculator;

	@Before
	public void init() {
		rpnCalculator = new RpnCalculator();
	}

	@Test
	public void subtractTwoNumbers() {
		rpnCalculator.push(new BigDecimal(4));
		rpnCalculator.push(new BigDecimal(-7));
		rpnCalculator.execute("-");
		assertEquals(11, rpnCalculator.peek());
	}

	@Test
	public void newlyCreatedCalcualtorHas0Value() {
		assertEquals(0, rpnCalculator.peek());
	}
}
